Digital Electronics- The 8051 Microcontroller
Digital Electronics- The 8051 Microcontroller
21. The 8-bit address bus allows access to an address range of:
- 0000 to FFFFH
- 000 to FFFH
- 00 to FFH
- 0 to FH
22. The contents of the accumulator after this operation
MOV A,#0BH
ANL A,#2CH
will be
MOV A,#0BH
ANL A,#2CH
will be
- 11010111
- 11011010
- 00001000
- 00101000
24. Which of the following instructions will move the contents of register 3 to the accumulator?
- MOV 3R, A
- MOV R3, A
- MOV A, R3
- MOV A, 3R
25. Which of the following statements will add the accumulator and register 3?
- ADD @R3, @A
- ADD @A, R3
- ADD R3, A
- ADD A, R3
26. Data transfer from I/O to external data memory can only be done with the MOV command.
- TRUE
- FALSE
27. Which of the following commands will move the number 27H into the accumulator?
- MOV A, P27
- MOV A, #27H
- MOV A, 27H
- MOV A, @27
28. This program code will read data from port 0 and write it to port 2, and it will stop looping when bit 3 of port 2 is set:
STAT: MOV A, PO
MOV P2,A
JNB P2.3, STAT
STAT: MOV A, PO
MOV P2,A
JNB P2.3, STAT
- TRUE
- FALSE
29. Which of the following commands will move the value at port 3 to register 2?
- MOV P2, R3
- MOV R3, P2
- MOV 3P, R2
- MOV R2, P3